The problem is the boot and loading system.
We have a custom loader and boot sequence in the demos.

If somebody can provide the code for doing a loader/booter that works on microdisc and jasmin, I guess we can patch the demos.

It was already very complicated to get the demos to work both on Oric Atmos AND Telestrat, because the bootsector is not loaded at the same location...

The loader was written by Jede, who is not active anymore... the good thing is that all the demos use the same loader (except the very first one without music which use sedoric calls to load data), so if somebody can find how to adapt the code, it would work for all of them.

Humm, for the booter, I don't know if I could manage to do that... I don't feel enough experienced in the art of assembly language. I just start to understand all those pieces of code and all the mechanics that go around, but I do not have yet the dexterity to write some complicated stuff. I've learned a lot with your various sources

For the overlay memory, I think I've seen something in Theoric about it.... (not sure, but who knows). Anyway there is something in the FTDOS documentation about iyt :

For the sector read I think I have some clues, at least about how to call any Jasmin commands in C like it is already done with microdisc in the Lib.h of the OSDK.
Moreover, recently I've spent some time to read the Jasmin documentation, and there is also someting about the reading of sectors with Jasmin :

Would normaly make it work on Jasmin.
Now, what would be cool, is to have a way to detect which system we have, and then I could do a new release of the intro which would work on Jasmin and Microdisc, or display an error message if the disk drive is not present.

(This particular intro does not read anything on the disk, it's just for the additional 16k)

Drive interfaces for the oric are all driven by the same family of FDC (floppy disc controllers): Western Digital 177x for the Jasmin and new 179x generation for the Microdisc (and Telestrat). Differences in this family exist to connect negative or positive drives, and to allow double-density formats (MFM mode). The FDC 1773 of the Jasmin and the 1793 of the Microdisc are compatible, but the additional circuitry is quite different so the programming routines have to be deeply adapted from one to the other (the telestrat has a second ULA integrating the Microdisc electronics, so it is largely compatible with it). The FDC 1793 (or 1773) is accessible through locations 0310-0313 in Microdisc's electronics, and 03F4-03F7 in Jasmin's electronics. This requires the interface to disable the internal VIA, with the use of the I/O CONTROL line on the system bus. See appendix for FDC programming commands

I put what is good as a start in green, and what I think is not cool at all in red

In blue, the link to the file.

Are there any mean to read at least a byte in the microdisc Rom (and in the Jasmin rom), in order to test for the value of this byte ? That would be a good test.
May be the difference in memory location is enough for this test (just have to test both locations) ?

Download the Buggy Boy demo and patch it. In the file NONAME000.COM at offset 3F75 (or offset F531 in the DSK itself) there is the sequence "78 A9 FD 8D 14 03", if you replace it by "78 A9 01 8D FA 03" then you should have a Jasmin compatible file.

VDMSounds works far better, but you only need it if you do not want some crappy sound, that's it.

By the way, I imagine that just right after the Finish Bear,that the overlay memory is accessed, am I right ?
May be have we forgotten this in the patch :
"Mettre 127 dans #30E pour interdire les interruptions de la VIA"

I'm using the Overlay memory and the interruptions all over the place.
I have a custom IRQ handler which is perfectly happy to have the ROM out, because it was actually designed to work without the ROM enabled at all.